That’s always been the case, AI or not.
It just happens to be a lot worse now. Confidence through ignorance has come into the spotlight with the commoditization of LLMs.
In my experience, the people sending me garbage PRs with Claude are the same ones who wrote garbage code beforehand. Now there's just 10x more of it.
No, it hasn't. I did not have a problem before AI with people sending in gigantic pull requests that made absolutely no sense, and justifying them with generated responses that they clearly did not understand. This is not a thing that used to happen. That's not to say people wouldn't have done it if it were possible, but there was a barrier to submitting a pull request that no longer exists.